A non-volatile memory device, described herein, comprises: a plurality of memory strings and at least one control circuit in communication with the non-volatile memory cell array. The at least one control circuit is configured to perform, for the plurality of memory strings, one erase-verify iteration in an erase operation including determining whether at least one memory string of the plurality of memory strings passes an erase-verify test. The at least one control circuit is configured to, if the at least one memory string passes the erase-verify test, inhibit the at least one memory string for erase including ramping up, to an erase voltage, of a voltage applied to a gate of a SGD transistor of the at least one memory string and to perform a next erase-verify iteration in the erase operation for remaining memory strings of the plurality of memory strings other than the at least one memory string.

To help reduce program disturbs in non-selected NAND strings of a non-volatile memory, a sub-block based boosting scheme in introduced. For a three dimensional NAND memory structure, in which the memory cells above a joint region form an upper sub-block and memory cells below the joint region form a lower sub-block, dummy word lines in the joint region act as select gates to allow boosting at the sub-block level when the lower block is being programmed in a reverse order.

Apparatus and methods are described to reduce program disturb for a memory string with a partial select gate drain, which is partially cut by a shallow trench. The memory string with a partial select gate drain is linked with a neighboring full select gate drain that during its programming can cause a program disturb in the memory string with a partial select gate drain. The bias voltage applied to the selected full select gate drain can be controlled from a high state for low memory program states to a lower state for the high memory program states. The high data states may cause program disturb. The reduction in the bias voltage can match a reduction in the bias voltage applied to the bit lines to reduce the program disturb while providing adequate signal to program the high states on the memory string of the full select gate drain.

The present technology relates to an electronic device. A memory device having improved memory block management performance according to the present technology includes a memory block, a peripheral circuit, and a control logic. The peripheral circuit performs a read operation and a program operation on a selected physical page among a plurality of physical pages. The control logic controls the peripheral circuit to read first logical page data stored in a first physical page and second logical page data stored in a second physical page among the plurality of physical pages, and additionally program the second logical page data into the first physical page using the read first and second logical page data.

A memory device comprises a memory control unit including a processor configured to control operation of the memory array according to a first memory management protocol for memory access operations, the first memory management protocol including boundary conditions for multiple operating conditions comprising program/erase (P/E) cycles, error management operations, drive writes per day (DWPD), and power consumption; monitor operating conditions of the memory array for the P/E cycles, error management operations, DWPD, and power consumption; determine when a boundary condition for one of the multiple operating conditions is met; and in response to determining that a first boundary condition for a first monitored operating condition is met, change one or more operating conditions of the first memory management protocol to establish a second memory management protocol for the memory access operations, the second memory management protocol including a change boundary condition of a second monitored operating condition.

According to one embodiment, a memory system includes a non-volatile memory and a controller. The memory includes a plurality of storage areas. Each of the storage areas includes a plurality of memory cells to which threshold voltages are set in accordance with data. The controller acquires a first threshold voltage distribution of memory cells in a first storage area of the storage areas. The controller acquires a second threshold voltage distribution of memory cells in a second storage area of the storage areas. The controller detects non-normalcy in the first storage area or the second storage area from a first divergence quantity between the first threshold voltage distribution and the second threshold voltage distribution.

A memory sub-system configured to use first values of a plurality of optimized read voltages to perform a first read calibration, which determines second values of the plurality of optimized read voltages. A plurality of shifts, from the first values to the second values respectively, can be computed for the plurality of optimized read voltages respectively. After recognizing a pattern in the plurality of shifts that are computed for the plurality of voltages respectively, the memory sub-system can control and/or initiate a second read calibration based on the recognized pattern in the shifts.

A flash memory cell includes a rectifying device and a transistor. The rectifying device has an input end coupled to a bit line. The transistor has a charge storage structure. The transistor has a first end coupled to an output end of the rectifying device, the transistor has a second end coupled to a source line, and a control end of the transistor is coupled to a word line.

A nonvolatile semiconductor memory device includes a control circuit configured to control a soft program operation of setting nonvolatile memory cells to a first threshold voltage distribution state of the nonvolatile memory cells. When a characteristic of the nonvolatile memory cells is in a first state, the control circuit executes the soft program operation by applying a first voltage for setting the nonvolatile memory cells to the first threshold voltage distribution state to first word lines, and applying a second voltage higher than the first voltage to a second word line. When the characteristic of the nonvolatile memory cells is in a second state, the control circuit executes the soft program operation by applying a third voltage equal to or lower than the first voltage to the first word lines and applying a fourth voltage lower than the second voltage to the second word line.

A memory system includes a nonvolatile memory which comprises a plurality of memory cells capable of storing 4-bit data represented by first to fourth bits by sixteen threshold regions, and a memory controller configured to cause the nonvolatile memory to execute a first program for writing data of the first bit, the second bit, and the fourth bit and then causes the nonvolatile memory to execute a second program for writing data of the third bit. In fifteen boundaries existing between adjacent threshold regions among the first to sixteenth threshold regions, a maximum value of the number of first boundaries used for determining a value of the data of the first bit, the number of second boundaries used for determining a value of the data of the second bit, the number of third boundaries used for determining a value of the data of the third bit.